Early diagnosis via cost-effective screening of high risk subpopulation followed by effective treatments is the key for saving many lives of cancer patients. Proteases overexpressed in cancer cells and secreted into circulation have been used as drug targets for the development of protease inhibitors as well as biomarkers for diagnosis and therapeutic monitoring. In this project, a multi-discipline team intends to develop a nanoelectronic chip for rapid profiling activity of six proteases that are overexpressed in metastatic triple-negative breast cancer (TNBC) patients and use this information to identify signatures in breast cancer progression and therapeutic responsiveness. The team includes (1) Dr. Jun Li (PI, nanotechnology and biosensor, Kansas State University); (2) Dr. Duy H. Hua (synthetic medicinal chemistry, Kansas State University); (3) Dr. Meyya Meyyappan (nanotechnology and nanodevices, NASA Ames Research Center); and (4) Dr. Priyanka Sharma (cancer clinical research, the University of Kansas Medical Center). This project focuses on developing the PI?s previously demonstrated electronic device based on carbon nanofiber nanoelectrode arrays for simultaneous detection of the activity of six overexpressed proteases in TNBC, including cathepsin B, MMP-2, MMP-9, ADAM-10, ADAM- 17 and uPA. Hexapeptide substrates highly specific to the aforementioned proteases are covalently attached to the tips of embedded carbon nanofibers in a multiplexed electronic chip. The distal end of the hexapeptides is attached with an electrochemical reporter. Introducing the TNBC patient samples containing these proteases results in cleavage of corresponding hexapeptides, thereby releasing the electrochemical reporter and leading to an exponential decrease of the electrochemical signal. The protease activity can be derived from the decay time constant of the kinetic curves. This extremely sensitive biosensor technology will be fabricated into independently addressed 3x3 arrays and packaged in disposable fluidic cartridges. Using 18 hexapeptide substrates (3 for each protease) attached to different nanoelectrode arrays in two 3x3 electronic chips, reliable proteolytic activity profile of the aforementioned six proteases in TNBC can be quickly measured, which cannot be done with current technologies. This technique should greatly accelerate the speed of protease profiling in complex samples and facilitate detection of invasive TNBC from other breast cancers in its early stage. The change of the protease activity profile will be monitored and correlate it with the longitudinal cancer treatment responses.